It is often reported that there are about 30,000 denominations within the Protestant branch of Christianity alone. This often leads to the suggestion is that if so many different churches each claims to be the correct one, perhaps none of them are. Sometimes this point is made by Roman Catholics as a kind of argument against Protestantism, the implication being that since they are both far older and numerically far larger than any Protestant institution, it is more likely that theirs is the true faith. However, I’ve also seen this line of thinking used in support of arguments against Christianity in general. Looking at the splits over the centuries into so many Catholic, Orthodox, and Protestant groups, why should one believe any of them are true? The point can be generalized even further by looking at the large number of world religions and wondering aloud whether it is likely that any of them has it right.
It is not, however, true that each of the various Christian groups proclaims itself to be the One True Church. For Roman Catholics, that claim is still “on the books” so to speak, albeit with some nuanced language about how “many elements of sanctification and of truth are found outside of its visible structure” (see here, sec. 8). Eastern Orthodoxy, less institutionally unified than the Catholicism but much more so than Protestantism, makes similar claims about itself. For Catholics and Orthodox, their claims to being the authentic church are historical, based on an unbroken institutional line back to the Apostles, with their primary disagreement being whether St. Peter (and by extension, the Bishops of Rome throughout history) had authority over other bishops.
Protestant denominations typically do not claim to be the One True Church. Protestant churches do often write creeds or “statements of faith”, but rarely claim that their own institution is the only true church. Instead, they often hold up the Bible as their authority, rather than any church institution.
Some churches on the fringe of Christianity do make such a claim, usually based upon their founder having been given some special authority by God in modern times. The usual result of this is for such a church to be labeled as non-Christian by all groups (Catholic, Protestant, Orthodox) in the mainstream of historic Christianity. Such labeling can be controversial, as in the case of the Mormons, a group whose main institution (the LDS church) does consider itself to be the One True Church.
Personally, I do not subscribe to any particular institution as being the One True Church, nor do I subscribe to the inerrancy of the Bible. However, I have no automatic hostility towards churches that teach either of these. For my first twenty-five years, I was a Roman Catholic, and I can assure anyone that the main business of that church (as I experienced it on a local level) is not bad-mouthing other churches (nor is it child abuse). I consider the Catholic Church overall to be a good institution, and I left it with no hard feelings, only because I found other institutions to be a bit better fit, in terms of helping me follow Jesus in my own life and pass the faith along to my children.
Intellectually, I am most at home in churches, such as the United Methodist Church, that encourage a Christian discipleship that draws upon scripture, tradition, reason, and experience, and that engages the contemporary culture, and that do not insist upon the inerrancy of the Bible (see here, here). I can also manage to find a place in churches, such as the Vineyard, that lean more conservative in their theology but think of themselves as a “centered set” rather than a “bounded set”.
Above all else, I am drawn towards congregations of any denomination that are focused on following Jesus and loving one another, which after all is the standard He set for recognizing His disciples. I would advise anyone looking for a church home to focus first on finding that – a love that not only fills the building each Sunday but also lingers in the heart all week, and spills out into the surrounding community.